The present invention relates generally to the art of infrared thermography and, more particularly, to a system which facilitates the collection of data by a thermographer, the efficient preparation of reports, and the archiving of records relating to thermographic inspection. The invention further relates to automating the process of field data collection, for complete and efficient documentation of thermographic events.
Infrared thermography, whereby infrared cameras are employed to acquire infrared images at any one of several infrared wavelength ranges, is known to be useful in a wide variety of applications. An observed anomaly or problem is known as a thermographic "event" to be reported and possibly diagnosed. The invention is disclosed herein in the context of industrial plant maintenance, also known as preventative maintenance or predictive maintenance. However, by way of example, and not limitation, infrared thermography is useful in a variety of applications other than plant maintenance, such as EPA studies, agriculture, medical technology, law enforcement, veterinary medicine and military uses.
As one example of a plant maintenance application, an infrared image of the interior of a three phase electric motor switch box may reveal that one fuse out of three, or the fuse connectors, is hotter than the other two, indicating a potential problem to be corrected before an actual failure occurs.
As another example, within a three phase electrical control box, a conductor associated with one of the phases may be colder than corresponding conductors associated with the other two phases, indicating that less current is being carried, and pointing to a potential problem to be investigated.
As other examples, within the exemplary context of industrial plant maintenance, the following components may advantageously be inspected employing infrared thermography: transformers, transformer control cubicles, motor control centers, transmission lines, electric motors, steam traps, pipes, valves, belts, components subject to vacuum leaks, insulation in general, roofs and roof insulation, dry type transformers, rotary kilns, auxiliary transformers, start up transformers, distribution panel circuit breakers, relays and ground straps.
Prior art infrared thermography systems have been labor intensive and relatively inefficient from the viewpoint of enabling a thermographer to rapidly and efficiently generate reports. Moreover, prior art thermography systems rely a great deal upon the skill and experience of the thermographer, and it may take two or three years for a thermographer to become well qualified.
In the context of the present invention, it may be noted that there are known prior art thermography systems which employ infrared cameras connected to a videotape recorder whereby a thermographer can record infrared images of various pieces of equipment and other things for later review. Later, when the thermographer is preparing a report, the videotape is played until desired images are found, which are displayed on a screen, and then captured for a permanent record, either photographically off of the video screen, or digitally.
Another prior art approach to thermography employs an infrared camera having what is in effect "snapshot" capability whereby a limited number of thermographic images, for example thirty three images, may be digitally captured to a floppy disk included within the infrared camera, for later review.
In prior art thermography systems, visible images are typically also captured, either employing a separate visible image video camera or a conventional photographic snapshot camera. While images are being captured, the thermographer makes notes of various observations as necessary to facilitate later preparation of a report.
These prior art approaches are highly labor intensive, particularly when reports are being prepared. It is not unusual for each hour a thermographer spends in the field to result in one or two days of time spent reducing data and preparing reports. Typically, while generating reports, the thermographer spends many hours looking through videotape images looking for particular thermographic events to document.
In the context of the present invention, it is also pertinent to note that there are prior art systems which employ computers to aid the thermographer. Typically, these computers are employed as a data analysis tool, such as to manipulate thermographic images for identifying specific values, average temperature over some area, isotherms, or line temperature profiles, rather than for purposes of documentation.